potrero
Mechanical
- Aug 30, 2007
- 516
NX6.0.1.5 MP1, Advanced Simulation
When modeling with 2D shells, which is the preferred method to join T-joints (ie where a rib connects to a face):
a) Stitch Edges
b) 1D Connection, Edge to Face
In my experience, the benefit of Stitch Edges is that the edges become truly coincident (non-free ... if you do a Check for Free Edges, the Stitched edges will not show up as free), so the meshes are coincident.
However, a big downside of Stitch Edges is stability, or lack thereof. Oftentimes if the model geometry changes, Stitch Edges will fail or cause memory errors, sometimes leading to really unstable parts (and thus requiring a complete re-do of the FEM. Bigtime pain.) It's also not really possible to "audit" the Stitch Edges - once they're Stitched, it's really difficult to go back and figure out how they were stitched. And sometimes, Stitch order matters...
On the other hand, the 1D connection might be a little more stable. It doesn't result in truly coincident meshes, which may or may not be a bad thing. I can't comment on stability when the original CAD model changes, yet.
It would be great to hear others' thoughts on best practices for doing rib-to-face connections with 2D shell geometry.
Thanks.
When modeling with 2D shells, which is the preferred method to join T-joints (ie where a rib connects to a face):
a) Stitch Edges
b) 1D Connection, Edge to Face
In my experience, the benefit of Stitch Edges is that the edges become truly coincident (non-free ... if you do a Check for Free Edges, the Stitched edges will not show up as free), so the meshes are coincident.
However, a big downside of Stitch Edges is stability, or lack thereof. Oftentimes if the model geometry changes, Stitch Edges will fail or cause memory errors, sometimes leading to really unstable parts (and thus requiring a complete re-do of the FEM. Bigtime pain.) It's also not really possible to "audit" the Stitch Edges - once they're Stitched, it's really difficult to go back and figure out how they were stitched. And sometimes, Stitch order matters...
On the other hand, the 1D connection might be a little more stable. It doesn't result in truly coincident meshes, which may or may not be a bad thing. I can't comment on stability when the original CAD model changes, yet.
It would be great to hear others' thoughts on best practices for doing rib-to-face connections with 2D shell geometry.
Thanks.